Psychology Essay 4

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Psychology Twelfth Edition

Chapter 5 Body Rhythms and

Mental States

Biological Rhythms: The Tides of

Experience

• LO 5.1.A Define circadian rhythms, and explain

how the body’s “biological clock” works (and what

happens when it doesn’t).

• LO 5.1.B Explain why seasonal affective disorder

and premenstrual syndrome are examples of long-

term biological rhythms, and summarize the

evidence regarding the existence of both

phenomena.

Circadian Rhythms (1 of 5)

• Consciousness is the awareness of oneself and

the environment.

• Throughout the day, mood, alertness, efficiency,

and consciousness itself are in perpetual flux.

• One way to understand consciousness is to study

how it changes over time.

– Mental and physical states are intertwined.

• Examining a person’s ongoing rhythmic cycles is

like watching a video of consciousness.

Circadian Rhythms (2 of 5)

• Changing states of consciousness are often

associated with biological rhythms.

• A biological clock in our brains governs:

– the waxing and waning of hormone levels

– urine volume

– blood pressure

– the responsiveness of brain cells to stimulation

Circadian Rhythms (3 of 5)

• Biological rhythms are typically in tune with:

– external time cues, such as changes in clock time,

temperature, daylight

• Many rhythms continue to occur even in the

absence of such cues.

– endogenous, generated from within

• Circadian fluctuations:

– occur about once a day

– are governed by a biological clock in the

suprachiasmatic nucleus (SCN) of the hypothalamus

Circadian Rhythms (4 of 5)

• The SCN regulates and, in turn, is affected by the

hormone melatonin.

• Melatonin is responsive to changes in light and

dark and increases during the dark hours.

– secreted by the pineal gland, deep within the brain

– induces sleep

– helps keep biological clock in phase with light–dark

cycle

Circadian Rhythms (5 of 5)

• When our normal routine changes, we may

experience internal desynchronization.

– Example: taking airplane flights across time zones

• The usual circadian rhythms are thrown out of

phase with one another.

– Sleep and wake patterns adjust quickly but

temperature and hormone cycles can take days to

return to normal.

– Jet lag affects energy level, mental skills, motor

coordination.

Moods and Long-Term Rhythms (1 of 5)

• Some people experience depression every winter

in a pattern that has been labeled seasonal

affective disorder (SAD).

• During the winter months, SAD patients report:

– feelings of sadness

– lethargy

– drowsiness

– craving for carbohydrates

Moods and Long-Term Rhythms (2 of 5)

• The causes of SAD, which is relatively

uncommon, are not yet clear.

• SAD is not recognized as an official disorder.

– Much of the research to date has been flawed.

• Light treatments can be effective in alleviating

symptoms.

• SAD may occur in people whose circadian

rhythms are out of sync.

– In essence, they have a chronic form of jet lag.

Moods and Long-Term Rhythms (3 of 5)

• Another long-term rhythm is the menstrual cycle,

during which various hormones rise and fall.

• Well-controlled, double-blind studies have been

conducted on premenstrual syndrome.

• These studies do not support claims that

emotional symptoms are reliably and universally

tied to the menstrual cycle.

Moods and Long-Term Rhythms (4 of 5)

• How both sexes interpret bodily and emotional

changes is affected by:

– expectations

– learning

• Few people of either sex are likely to undergo

dramatic monthly mood swings or personality

changes because of hormones.

Moods and Long-Term Rhythms (5 of 5)

Figure 5.1

Mood Changes in Men and Women

(McFarlane, Martin, & Williams, 1988)

The Rhythms of Sleep

• LO 5.2.A Describe the four stages of sleep, and

explain the primary features of each stage.

• LO 5.2.B List the mental consequences of

sleeplessness and the mental benefits of a good

night’s sleep.

The Realms of Sleep (1 of 6)

• During sleep, periods of rapid eye movement

(REM) alternate with non-REM (NREM) sleep in

approximately a 90-minute rhythm.

• The REM periods last from a few minutes to as

long as an hour.

• They average about 20 minutes in length.

The Realms of Sleep (2 of 6)

• Non-REM sleep is divided into stages on the basis

of characteristic brain-wave patterns.

• Alpha waves gradually slow down, passing

through three stages, each deeper than the

previous one:

– Stage NREM-1

– Stage NREM-2

 sleep spindles

– Stage NREM-3

 delta waves

The Realms of Sleep (3 of 6)

• During REM sleep, the brain is active, and there

are other signs of arousal.

• Most of the skeletal muscles are limp.

• Vivid dreams are reported most often during REM

sleep.

• REM and non-REM sleep continue to alternate

throughout the night.

The Realms of Sleep (4 of 6)

Figure 5.2

Brain-Wave Patterns during Wakefulness and Sleep

The Realms of Sleep (5 of 6)

Figure 5.3

A Typical Night’s Sleep for a Young Adult

The Realms of Sleep (6 of 6)

Table 5.1

Characteristics of Sleep Stages

REM sleep Active brain but inactive muscles

NREM-1 Period when the sleeper is on the edge of

consciousness, in a light sleep

NREM-2 Sleep stage characterized by short bursts of

rapid waves

NREM-3 Sleep stage characterized by very slow

waves with high peaks

Alpha waves Brain activity during a state of relaxed

wakefulness

Sleep spindles Short, high-peaking waves

Delta waves Waves present during deep sleep

Why We Sleep (1 of 4)

• Sleep is necessary for:

– bodily restoration

– normal mental functioning

• Sleep appears to provide a time-out period, so

that the body can:

– eliminate waste products from muscles

– repair cells

– conserve or replenish energy stores

– strengthen the immune system

– recover abilities lost during the day

Why We Sleep (2 of 4)

• Many people get less than the optimal amount of

sleep, perhaps suffering from:

– insomnia

– sleep apnea

– narcolepsy

– REM behavior disorder

• The most common reason for daytime sleepiness

is probably a simple lack of sleep.

– Most adults need more than 6 hours for optimal

performance, and many adolescents need 10.

Why We Sleep (3 of 4)

• Sleep may contribute to:

– the consolidation of memories

– subsequent problem solving

• These benefits have been associated most closely

with slow-wave sleep.

– also with REM sleep

• The underlying biology appears to involve:

– the formation of new synaptic connections

– the weakening of connections that are no longer

needed

Why We Sleep (4 of 4)

Figure 5.4

Sleep and Consolidation in Memory

Exploring the Dream World

• LO 5.3.A Discuss explanations for why we dream.

• LO 5.3.B Summarize the strengths and

weaknesses of each major dream theory.

Explanations of Dreaming (1 of 7)

• Freud thought that:

– dreams allow us to express forbidden or unrealistic

desires

– these desires have been forced into the unconscious

part of the mind

• There is no objective way to verify Freudian

interpretations of dreams.

• There is no convincing support for most of his

claims.

Explanations of Dreaming (2 of 7)

• Three modern theories of dreaming emphasize

the connections between dreams and waking

thoughts:

– problem-focused approach

– cognitive approach

– activation–synthesis theory

Explanations of Dreaming (3 of 7)

• The problem-focused approach holds that:

– dreams express current concerns

– may even help us solve current problems

• In this approach, the symbols and metaphors in a

dream:

– do not disguise its true meaning

– they actually convey it

• Example of problem focus in dreams: Text-anxiety

dreams are common among college students.

Explanations of Dreaming (4 of 7)

• The cognitive approach holds that dreams are

simply a modification of the cognitive activity that

goes on when we are awake.

• Thus, the content of our dreams may include:

– thoughts,

– concepts, and

– scenarios that may or may not be related to our daily

problems

Explanations of Dreaming (5 of 7)

• The difference is that during sleep:

– we are cut off from sensory input from the world

– our thoughts tend to be more diffuse and unfocused

– the only input to the brain is its own output

• The brain shows similar patterns of activity when

we are night dreaming as when we are

daydreaming.

– suggests that nighttime dreaming might be a

mechanism for simulating events that we think (or fear)

might occur in the future

Explanations of Dreaming (6 of 7)

• The activation–synthesis theory holds that dreams

occur when the cortex tries to make sense of, or

interpret, spontaneous neural firing initiated in the

pons.

• Dreams result from the cortex’s synthesis of:

– signals from pons

– existing knowledge

– memories

• In this view, wishes do not cause dreams; brain

mechanisms do.

Explanations of Dreaming (7 of 7)

Page 159

Evaluating Dream Theories (1 of 2)

• All of the current theories of dreams have some

support, and all have weaknesses.

• Regarding the problem-solving approach:

– Some psychologists doubt that people can solve

problems during sleep.

– Dreams merely give expression to our problems.

– The same insights obtained from dreaming could occur

while awake.

Evaluating Dream Theories (2 of 2)

• The activation–synthesis theory has been

criticized, as it does not seem to explain:

– coherent, story-like dreams

– non-REM dreams

• The cognitive approach is now a leading

contender.

– some of its specific claims remain to be tested

• Perhaps it will turn out that different kinds of

dreams have different purposes and origins.

The Riddle of Hypnosis

• LO 5.4.A Summarize six established facts about

hypnosis, and outline the truth and misconceptions

associated with each.

• LO 5.4.B Contrast the dissociation theory of

hypnosis from the sociocognitive approach, noting

how each accounts for aspects of hypnotized

behavior.

The Nature of Hypnosis (1 of 4)

• Hypnosis is a procedure in which the practitioner

suggests changes in a person’s:

– sensations

– perceptions

– thoughts

– feelings

– behavior

• The person tries to alter their cognitive processes

to comply with the hypnotist’s suggestions.

The Nature of Hypnosis (2 of 4)

• Hypnosis has been used successfully for many

medical and psychological purposes.

• Some worry that thinking of hypnosis as a kind of

“dark art” has interfered with understanding it.

• People hold many misconceptions about what it

can accomplish.

The Nature of Hypnosis (3 of 4)

• Hypnotic responsiveness depends more on the

efforts and qualities of the person being

hypnotized than on the skill of the hypnotist.

• Hypnosis cannot:

– force people to do things against their will

– confer special abilities that are otherwise impossible

– increase the accuracy of memory

– produce a literal re-experiencing of long ago events

The Nature of Hypnosis (4 of 4)

• Hypnosis been used in the treatment of:

– pain management

– stress

– anxiety

– obesity

– asthma

– irritable bowel syndrome

– chemotherapy-induced nausea

– skin disorders

Theories of Hypnosis (1 of 6)

• A leading approach to understanding hypnosis is

that it involves dissociation, a split in

consciousness.

• In one version of this approach, the split is

between:

– a part of consciousness that is hypnotized

– a hidden observer that watches but does not

participate

Theories of Hypnosis (2 of 6)

• In another version, the split is between:

– an executive-control system in the brain

– other brain systems responsible for thinking and acting

• In hypnosis, the executive system turns off and

hands its function over to the hypnotist.

• That leaves the hypnotist able to suggest how we

should interpret the world and act in it.

Theories of Hypnosis (3 of 6)

• The sociocognitive explanation regards hypnosis

as a product of normal social and cognitive

processes.

• There is a combination of:

– the hypnotized person’s expectations and beliefs

– the desire to comply with the hypnotist’s suggestions

• In this view, hypnosis is a form of role-playing.

• The role is so engrossing that the person

interprets it as real.

Theories of Hypnosis (4 of 6)

• Sociocognitive processes can account for:

– the apparent age and past life “regressions” of people

under hypnosis

– reports of alien abductions

Theories of Hypnosis (5 of 6)

Figure 5.5

Dissociation Theories of Hypnosis

Theories of Hypnosis (6 of 6)

Figure 5.6

Sociocognitive Theories of Hypnosis

Consciousness-Altering Drugs

• LO 5.5.A List the four main categories of

psychoactive drugs, and summarize the main

effects of each.

• LO 5.5.B Outline the physiology of drug effects,

and explain the process by which biochemical

changes take place.

• LO 5.5.C Summarize four psychological aspects of

drug effects, and comment on how each one might

moderate physiological drug effects.

Classifying Drugs (1 of 3)

• In all cultures, people have found ways to produce

altered states of consciousness.

• Psychoactive drugs alter cognition and emotion by

acting on neurotransmitters in the brain.

• They affect:

– mood

– thinking

– memory

– behavior

Classifying Drugs (2 of 3)

• Most psychoactive drugs are classified as:

– stimulants

– depressants

– opiates

– psychedelics

• Classification depends on their:

– central nervous system effects

– impact on behavior and mood

Classifying Drugs (3 of 3)

• However, some common drugs, such as

marijuana, straddle or fall outside these

categories.

• Some classify it as a psychedelic; others place it

outside the major classifications because of its:

– chemical makeup

– psychological effects

• Heavy smoking of the drug (which is high in tar)

may increase the risk of lung damage.

The Physiology of Drug Effects (1 of 3)

• Biochemical changes from psychoactive drugs

affect cognitive and emotional functioning.

• When used frequently and in large amounts, some

psychoactive drugs can:

– damage neurons in the brain

– impair learning and memory

• Their use may lead to:

– tolerance, in which increasing dosages are needed for

the same effect

– withdrawal symptoms if a heavy user tries to quit

The Physiology of Drug Effects (2 of 3)

• But certain drugs, such as alcohol and marijuana,

are also associated with some health benefits

when used in moderation.

The Physiology of Drug Effects (3 of 3)

Figure 5.7

Cocaine’s Effect on the Brain

The Psychology of Drug Effects (1 of 2)

• Reactions to a psychoactive drug are influenced

not only by its chemical properties but also by:

– the user’s prior experience with the drug

– individual characteristics (body weight, metabolism,

initial state of emotional arousal, personality

characteristics, physical tolerance for the drug)

– environmental setting

– mental set—the person’s expectations and motives for

taking the drug

The Psychology of Drug Effects (2 of 2)

• Expectations can be even more powerful than the

drug itself, as shown by the “think–drink” effect.

– Example: Men behaved more belligerently when they

thought they were drinking vodka than when they

thought they were drinking plain tonic water.

• This does not mean that alcohol and other drugs

are merely placebos.